u-boot/drivers/spi/xilinx_spi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Xilinx SPI driver
*
* Supports 8 bit SPI transfers only, with or w/o FIFO
*
* Based on bfin_spi.c, by way of altera_spi.c
* Copyright (c) 2015 Jagan Teki <jteki@openedev.com>
* Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
* Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
* Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
* Copyright (c) 2005-2008 Analog Devices Inc.
*/
#include <config.h>
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#include <wait_bit.h>
#include <linux/bitops.h>
/*
* [0]: http://www.xilinx.com/support/documentation
*
* Xilinx SPI Register Definitions
* [1]: [0]/ip_documentation/xps_spi.pdf
* page 8, Register Descriptions
* [2]: [0]/ip_documentation/axi_spi_ds742.pdf
* page 7, Register Overview Table
*/
/* SPI Control Register (spicr), [1] p9, [2] p8 */
#define SPICR_LSB_FIRST BIT(9)
#define SPICR_MASTER_INHIBIT BIT(8)
#define SPICR_MANUAL_SS BIT(7)
#define SPICR_RXFIFO_RESEST BIT(6)
#define SPICR_TXFIFO_RESEST BIT(5)
#define SPICR_CPHA BIT(4)
#define SPICR_CPOL BIT(3)
#define SPICR_MASTER_MODE BIT(2)
#define SPICR_SPE BIT(1)
#define SPICR_LOOP BIT(0)
/* SPI Status Register (spisr), [1] p11, [2] p10 */
#define SPISR_SLAVE_MODE_SELECT BIT(5)
#define SPISR_MODF BIT(4)
#define SPISR_TX_FULL BIT(3)
#define SPISR_TX_EMPTY BIT(2)
#define SPISR_RX_FULL BIT(1)
#define SPISR_RX_EMPTY BIT(0)
/* SPI Data Transmit Register (spidtr), [1] p12, [2] p12 */
#define SPIDTR_8BIT_MASK GENMASK(7, 0)
#define SPIDTR_16BIT_MASK GENMASK(15, 0)
#define SPIDTR_32BIT_MASK GENMASK(31, 0)
/* SPI Data Receive Register (spidrr), [1] p12, [2] p12 */
#define SPIDRR_8BIT_MASK GENMASK(7, 0)
#define SPIDRR_16BIT_MASK GENMASK(15, 0)
#define SPIDRR_32BIT_MASK GENMASK(31, 0)
/* SPI Slave Select Register (spissr), [1] p13, [2] p13 */
#define SPISSR_MASK(cs) (1 << (cs))
#define SPISSR_ACT(cs) ~SPISSR_MASK(cs)
#define SPISSR_OFF ~0UL
/* SPI Software Reset Register (ssr) */
#define SPISSR_RESET_VALUE 0x0a
#define XILSPI_MAX_XFER_BITS 8
#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | SPICR_MASTER_MODE | \
SPICR_SPE)
#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | SPICR_MANUAL_SS)
#define XILINX_SPI_IDLE_VAL GENMASK(7, 0)
#define XILINX_SPISR_TIMEOUT 10000 /* in milliseconds */
/* xilinx spi register set */
struct xilinx_spi_regs {
u32 __space0__[7];
u32 dgier; /* Device Global Interrupt Enable Register (DGIER) */
u32 ipisr; /* IP Interrupt Status Register (IPISR) */
u32 __space1__;
u32 ipier; /* IP Interrupt Enable Register (IPIER) */
u32 __space2__[5];
u32 srr; /* Softare Reset Register (SRR) */
u32 __space3__[7];
u32 spicr; /* SPI Control Register (SPICR) */
u32 spisr; /* SPI Status Register (SPISR) */
u32 spidtr; /* SPI Data Transmit Register (SPIDTR) */
u32 spidrr; /* SPI Data Receive Register (SPIDRR) */
u32 spissr; /* SPI Slave Select Register (SPISSR) */
u32 spitfor; /* SPI Transmit FIFO Occupancy Register (SPITFOR) */
u32 spirfor; /* SPI Receive FIFO Occupancy Register (SPIRFOR) */
};
/* xilinx spi priv */
struct xilinx_spi_priv {
struct xilinx_spi_regs *regs;
unsigned int freq;
unsigned int mode;
unsigned int fifo_depth;
u8 startup;
};
static int xilinx_spi_probe(struct udevice *bus)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
priv->regs = (struct xilinx_spi_regs *)dev_read_addr(bus);
priv->fifo_depth = dev_read_u32_default(bus, "fifo-size", 0);
writel(SPISSR_RESET_VALUE, &regs->srr);
return 0;
}
static void spi_cs_activate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_ACT(cs), &regs->spissr);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
}
static int xilinx_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_ON, &regs->spicr);
return 0;
}
static int xilinx_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_OFF, &regs->spicr);
return 0;
}
static u32 xilinx_spi_fill_txfifo(struct udevice *bus, const u8 *txp,
u32 txbytes)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
unsigned char d;
u32 i = 0;
while (txbytes && !(readl(&regs->spisr) & SPISR_TX_FULL) &&
i < priv->fifo_depth) {
d = txp ? *txp++ : XILINX_SPI_IDLE_VAL;
debug("spi_xfer: tx:%x ", d);
/* write out and wait for processing (receive data) */
writel(d & SPIDTR_8BIT_MASK, &regs->spidtr);
txbytes--;
i++;
}
return i;
}
static u32 xilinx_spi_read_rxfifo(struct udevice *bus, u8 *rxp, u32 rxbytes)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
unsigned char d;
unsigned int i = 0;
while (rxbytes && !(readl(&regs->spisr) & SPISR_RX_EMPTY)) {
d = readl(&regs->spidrr) & SPIDRR_8BIT_MASK;
if (rxp)
*rxp++ = d;
debug("spi_xfer: rx:%x\n", d);
rxbytes--;
i++;
}
debug("Rx_done\n");
return i;
}
static void xilinx_spi_startup_block(struct udevice *dev, unsigned int bytes,
const void *dout, void *din)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
const unsigned char *txp = dout;
unsigned char *rxp = din;
u32 reg;
u32 txbytes = bytes;
u32 rxbytes = bytes;
/*
* This loop runs two times. First time to send the command.
* Second time to transfer data. After transferring data,
* it sets txp to the initial value for the normal operation.
*/
for ( ; priv->startup < 2; priv->startup++) {
xilinx_spi_fill_txfifo(bus, txp, txbytes);
reg = readl(&regs->spicr) & ~SPICR_MASTER_INHIBIT;
writel(reg, &regs->spicr);
xilinx_spi_read_rxfifo(bus, rxp, rxbytes);
txp = din;
if (priv->startup) {
spi_cs_deactivate(dev);
spi_cs_activate(dev, slave_plat->cs);
txp = dout;
}
}
}
static int xilinx_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
/* assume spi core configured to do 8 bit transfers */
unsigned int bytes = bitlen / XILSPI_MAX_XFER_BITS;
const unsigned char *txp = dout;
unsigned char *rxp = din;
u32 txbytes = bytes;
u32 rxbytes = bytes;
u32 reg, count;
int ret;
debug("spi_xfer: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n",
dev_seq(bus), slave_plat->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
if (bitlen % XILSPI_MAX_XFER_BITS) {
printf("XILSPI warning: Not a multiple of %d bits\n",
XILSPI_MAX_XFER_BITS);
flags |= SPI_XFER_END;
goto done;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev, slave_plat->cs);
/*
* This is the work around for the startup block issue in
* the spi controller. SPI clock is passing through STARTUP
* block to FLASH. STARTUP block don't provide clock as soon
* as QSPI provides command. So first command fails.
*/
xilinx_spi_startup_block(dev, bytes, dout, din);
while (txbytes && rxbytes) {
count = xilinx_spi_fill_txfifo(bus, txp, txbytes);
reg = readl(&regs->spicr) & ~SPICR_MASTER_INHIBIT;
writel(reg, &regs->spicr);
txbytes -= count;
if (txp)
txp += count;
ret = wait_for_bit_le32(&regs->spisr, SPISR_TX_EMPTY, true,
XILINX_SPISR_TIMEOUT, false);
if (ret < 0) {
printf("XILSPI error: Xfer timeout\n");
return ret;
}
debug("txbytes:0x%x,txp:0x%p\n", txbytes, txp);
count = xilinx_spi_read_rxfifo(bus, rxp, rxbytes);
rxbytes -= count;
if (rxp)
rxp += count;
debug("rxbytes:0x%x rxp:0x%p\n", rxbytes, rxp);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
return 0;
}
static int xilinx_spi_set_speed(struct udevice *bus, uint speed)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
priv->freq = speed;
debug("xilinx_spi_set_speed: regs=%p, speed=%d\n", priv->regs,
priv->freq);
return 0;
}
static int xilinx_spi_set_mode(struct udevice *bus, uint mode)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
uint32_t spicr;
spicr = readl(&regs->spicr);
if (mode & SPI_LSB_FIRST)
spicr |= SPICR_LSB_FIRST;
if (mode & SPI_CPHA)
spicr |= SPICR_CPHA;
if (mode & SPI_CPOL)
spicr |= SPICR_CPOL;
if (mode & SPI_LOOP)
spicr |= SPICR_LOOP;
writel(spicr, &regs->spicr);
priv->mode = mode;
debug("xilinx_spi_set_mode: regs=%p, mode=%d\n", priv->regs,
priv->mode);
return 0;
}
static const struct dm_spi_ops xilinx_spi_ops = {
.claim_bus = xilinx_spi_claim_bus,
.release_bus = xilinx_spi_release_bus,
.xfer = xilinx_spi_xfer,
.set_speed = xilinx_spi_set_speed,
.set_mode = xilinx_spi_set_mode,
};
static const struct udevice_id xilinx_spi_ids[] = {
{ .compatible = "xlnx,xps-spi-2.00.a" },
{ .compatible = "xlnx,xps-spi-2.00.b" },
{ }
};
U_BOOT_DRIVER(xilinx_spi) = {
.name = "xilinx_spi",
.id = UCLASS_SPI,
.of_match = xilinx_spi_ids,
.ops = &xilinx_spi_ops,
.priv_auto = sizeof(struct xilinx_spi_priv),
.probe = xilinx_spi_probe,
};